Role of rho NN tensor coupling and 2s(1/2) occupation in light exotic nuclei

We study the properties of light neutron-rich exotic nuclei with relativistic-mean-field models. The nonlinear isoscalar-isovector term that is not constrained by the present data is considered. The {rho}NN tensor coupling is included. The data-to-data correlation between the neutron radius of {sup 208}Pb and that of light exotic oxygen, fluorine, and neon isotopes is enhanced by the inclusion of the {rho}NN tensor coupling subject to the 2s{sub 1/2} occupation of the outlayer neutrons. This enhancement is determined by the single-particle property rather than by the bulk-matter property. The role of the {rho}NN tensor coupling and the pairing correlation in reducing the model dependence of the neutron thickness in light exotic nuclei is investigated. The influence of the isoscalar-isovector term on halo neutrons, characteristic of the 2s{sub 1/2} occupation, is discussed.